Warded Soul

Benefit: When you gain a negative level, you may immediately make a Fortitude save to shrug off the effects. If you fail the initial save, you may attempt a second save in 24 hours at a +4 bonus.

Undead that use enervating attacks that bestow negative levels gain only half the normal number of temporary hit points when attacking you (rounded down). Additionally, you can never be affected by an undead creature’s create spawn ability.